OH3 how to use map transform in ECMA Rules

Setup, Configuration and Use Scripts & Rules
1

I’m moving my DSL rules into openHAB3 and I’d like to also move to EMCAscript while I’m at it.
first of all: there’s no GUI way to add map Transformations in openHAB3 yet, correct? You must copy the files to /etc/openhab/transform?

so, the main question: how can I migrate that DSL line to Javascript - and what do I need to import for that?

var String name = transform("MAP","mynames.map",Userid.state.toString())
1 Like
2

I’m interested too, can’t find a way through.

3

I’ve just come across this as I’m also looking for a way to access transform in ECMAScript.

4

You can do it without rule if it’s just an item you want to transform:
Just go to Things -> Channel -> Select Item. At the bottom you can choose a profile, select MAP and type the file name: mynames.map (this file is inside your /etc/openhab/transform)

5

I’m looking for it as I need to get the string in rule - currently I have duplicated the map as an array

6

It is possible to create your own solution and possibly adapt it to your needs:

this.maptransform = function(filename, parameter)
{
  var TypeMap = Java.type("java.util.HashMap");
  var TypeReader = Java.type("java.io.BufferedReader");
  var TypeFile = Java.type("java.io.FileReader");
  var file = new TypeFile(Java.type("java.lang.System").getenv("OPENHAB_CONF") + "/transform/" + filename);
  var reader = new TypeReader(file);
  var map = new TypeMap();
  
  var line = new String();
  var delimiter = "=";
  while ((line = reader.readLine()) != null)
  {
    if (line.trim().length()==0) continue;
    if (line.charAt(0)=='#') continue;
    var delimPosition = line.indexOf(delimiter);
    var key = line.substring(0, delimPosition).trim();
    var value = line.substring(delimPosition+1).trim();
    map.put(key, value);
  }
  reader.close();
  return map.get(parameter);
}

and calling:
var mapping = maptransform("config.map", "email");

2 Likes
7

@Dant Thanks a lot for this helpful snippet.

I’m migration all my rules from DSL to JS and wondering that a function like this isn’t available out of the box.
@rlkoshak Rich, Can you give perhaps some background information?

8

It is available out of the box. See Transformation (openHAB Core 3.1.0-SNAPSHOT API)

var Transformation = Java.type("org.openhab.core.transform.actions.Transformation");

Transformation.transform("MAP", "mynames.map", Userid.state.toString());

All the actions are available.

All of the other actions are available at org.openhab.core.model.script.actions (openHAB Core 3.1.0-SNAPSHOT API)

Interaction with Persistence is through PersistenceExtensions (openHAB Core 3.1.0-SNAPSHOT API)

4 Likes
9

Awesome! Thanks a lot @rlkoshak!
Wasn’t aware of it because it’s not mentioned in the docs Transformations | openHAB :frowning:

10

Thanks a lot!
Finally the solution I needed.
And what’s more now I think I am able to find other soultions myself using your documentation links.

Best Regards,
Uwe